The present invention relates to a polymer-combined drug having directional characteristics to digestive organs by which the drug is specifically carried into digestive organs, particularly the stomach or intestines, and to a method for producing the drug.
Hitherto, for carrying medicines having directional characteristics to the stomach or intestines, drugs such as an oral drug and a suppository should be administered to the internal organs directly or adjacently. When a medicine is administered intravenously, since the blood concentration is increased rapidly, the secondary effect of the medicine causes trouble. Further, since the medicine is excreted rapidly, there are problems such as low durability of the effect of the medicine and the like.
In polyalkyleneoxy compounds, particularly polyethylene glycol has low toxicity and non-immunogenicity. It is known widely that the compound administered orally or intravenously is little harmful for the human body. However, the movement of these compounds in the body after medication is little reported, and it is reported only that the compounds are rapidly excreted after intravenous injections.
In general, it is said that water-soluble materials having relatively high molecular weight are bad for permeability to a mucosa and they are little absorbed (M. D. Donovan et al, Pharmaceutical Res., Vol. 7, 863 (1990)).
As a mucosa of the digestive tract prevents absorption of water-soluble medicines which are orally administered, it is a serious obstacle to take effect by using various water-soluble medicines, such as ionic cholinolytics and peptide medicines.